The development of new algorithms for the management and state estimation of lithium-ion batteries requires their verification and performance assessment using different approaches and tools. This paper aims at presenting an advanced hardware in the loop platform that uses an accurate model of the battery to test the functionalities of battery management systems (BMSs) in electric vehicles. The developed platform sends the simulated battery data directly to the BMS under test via a communication link, ensuring the safety of the tests. As a case study, the platform has been used to test two promising battery state estimators, the adaptive mix algorithm and the dual extended Kalman filter, implemented on a field-programmable gate array-based BMS. The results show the importance of the assessment of these algorithms under different load profiles and conditions of the battery, thus highlighting the capabilities of the proposed platform to simulate many different situations in which the estimators will work in the target application.

Lipid lateral diffusion in membrane bilayers is a fundamental process exploited by cells to enable complex protein structural and dynamic reorganizations. For its importance, lipid mobility in both cellular and model bilayers has been extensively investigated in recent years, especially through the application of time-resolved, fluorescence-based, optical microscopy techniques. However, one caveat of fluorescence techniques is the need to use dye-labeled variants of the lipid of interest, thus potentially perturbing the structural and dynamic properties of the native species. Generally, the effect of the dye/tracer molecule is implicitly assumed to be negligible. Nevertheless, in view of the widespread use of optically modified lipids for studying lipid bilayer dynamics, it is highly desirable to well assess this point. Here, fluorescence correlation spectroscopy (FCS) and molecular dynamics (MD) simulations have been combined together to uncover subtle structural and dynamic effects in DOPC planar membranes enriched with a standard Rhodamine-labeled lipid. Our findings support a non-neutral role of the dye-labeled lipids in diffusion experiments, quantitatively estimating a decrease in lipid mobility of up to 20% with respect to the unlabeled species. Moreover, results highlight the existing interplay between dye concentration, lipid lateral diffusion and membrane permeability, thus suggesting possible implications for future optical microscopy studies of biophysical processes occurring at the membrane level.

Large-format Lithium-ion battery packs consist of the series and parallel connection of elemental cells, usually assembled into modules. The required voltage and capacity of the battery pack can be reached by various configurations of the elemental cells or modules. It is thus worth investigating if different configurations lead to different performance of the battery pack in presence of a mismatch in the cell characteristics. A simulation tool is developed in this work and applied to a battery pack consisting of standard 12 V modules connected with various serial/parallel topologies. The results show that battery configurations with modules directly connected in parallel and then assembled in series are more robust against variation of the cell capacity through the battery. Moreover, given the cells and the battery configuration, we show that changing the position of the cells has a significant impact on the usable capacity of the battery.

The progressive cost reduction of Lithium-ion batteries drives an everyday larger number of applications to enjoy the advantages of this energy storage technology. At the same time, issues like safety and charge unbalance in batteries with series-connected cells may limit the full exploitation of the technology, as charge unbalance reduces the usable capacity of the battery. This work describes a passive cell equalization procedure executed by the Battery Management System that reaches the balance of the battery with negligible additional costs. It is based on an iterative algorithm that progressively reduces in small consecutive steps the charge levels of the most charged cells by activating bleeding resistors. The algorithm takes into account the inaccuracies of the measurement of the cell voltages, the maximum possible balancing power, and reduces the effect of the cell short-term relaxation phenomena. It is fully parametric and can be tailored to any kind of battery. The algorithm is experimentally validated with a 10-cell Li-ion battery and its functionality is successfully demonstrated.